Showa Denko K.k.

Masako Tanaka

Akinori Sudoh

Yuuichi Kamijou

Yasuo Saito

Masataka Takeuchi

Yasuaki Wakizaka

Chiaki Sotowa

Tomohiro Abe

Takayuki Fukai

A graphite material having pores which, when 200 rectangular regions of 6 &#x3bc;m&#xd7;8 &#x3bc;m are randomly selected in a surface image of the graphite material observed by a scanning electron microscope, in the surface of the graphite material appearing in the regions, a pore appearing on the surface and having an aperture in a shape having a diameter of 15 nm to 200 nm, a circularity degree of 0.75 to 1.0 and a major axis/minor axis ratio of 1.0 to 1.5 is visible in two regions or more. Also disclosed is a carbon material for battery electrodes, a paste for electrodes, an electrode and a lithium ion secondary battery including the graphite material.

Graphite material, carbon material for battery electrode, and battery

A graphite material suitable as an electrode material for non-aqueous electrolytic secondary batteries; a method for producing the same and a carbon material for battery electrodes; and a secondary battery. The graphite material includes crystallite graphite particles wherein an oxygen amount (a) (mass %) in a region from a particle surface of the graphite material to a depth of 40 nm is within a range of 0.010&#x2266;(a)&#x2266;0.04 as determined by a peak intensity of Oobtained by HAX-PES measurement using a hard X-ray of 7,940 eV.

Graphite material, method for producing same, carbon material for battery electrodes, and battery

The present invention relates to an active carbon containing an alkaline earth metal compound inside the particle and having a specific surface area of 10 to 2,000 m/g, which is suitable to be used for polarizable electrodes in an electric double layer capacitor. The active carbon of the present invention enables to increase the capacitance of an electric double layer capacitor as well as to control the expansion of electrodes. The active carbon of the present invention can be obtained by adding an alkaline earth metal compound to a material such as pitch and performing heat treatment and activation.

Active carbon, production method thereof and polarizable electrode

An activated carbon material having a BET specific surface area of 10 to 1,000 m/g as measured by means of a nitrogen adsorption method, and the ratio of the height of the D peak (1,360 cm) of a Raman spectrum of the activated carbon material to that of the G peak (1,580 cm&#x2212;) of the Raman spectrum is 0.8 to 1.2. When the activated carbon material of the present invention is used as a polarizable electrode material of an electric double layer capacitor, high capacitance per electrode is attained without application of excessive voltage.

Activated carbon material, and production method and use thereof

A method for producing an activated carbon material, wherein the method comprises a step of thermally treating coal-based pitch at two temperature ranges of 400&#xb0; C. to 600&#xb0; C. and 600&#xb0; C. to 900&#xb0; C.; and a step of mixing the thus obtained carbonaceous material with an alkali metal compound and effecting activation thereof at 600&#xb0; C. to 900&#xb0; C., and an activated carbon material obtained by the method. When the activated carbon material of the present invention is used a polarizable electrode material of an electric double layer capacitor, high capacitance per electrode is attained without application of excessive voltage. By adding fibrous material to a coal-based pitch during activation expansion of an alkali molten liquid can be suppressed and productivity can be drastically improved. Furthermore, employment of an fibrous carbon material which is excellent in conductivity as a fibrous material, carbon fiber is melt-bonded on the surface of the activated carbon material, which enables production of a polarizable electrode exhibiting excellent charge/discharge characteristics at high current density.

Growing community of inventors

Tokyo, Japan

Masako Tanaka